1. Field of the Invention
The present invention relates to a manufacturing method of an image-sensing module, and more particularly, to a manufacturing method of a wafer level chip scale package of an image-sensing module.
2. Description of Related Art
The process of fabricating complementary metal-oxide-semiconductor (CMOS) image sensor and CMOS transistor are compatible. Therefore, image sensors along with other peripheral circuits can be easily integrated on the same chip to reduce overall production cost and power consumption. In recent years, CMOS image sensors are widely adopted in low-end applications and frequently serve as a replacement for charge-coupled devices. Consequently, the importance of CMOS image sensors is increasing every day.
FIG. 1A is a schematic diagram of a conventional CMOS image sensor, and FIG. 1B is an explosion view showing the components of the CMOS image sensor in FIG. 1A. As shown in FIGS. 1A and 1B, the conventional CMOS image sensor 100 includes a base 110, a CMOS chip 120 and a lens group 130. The CMOS chip 120 and the lens group 130 is disposed on the base 110 and the lens group 130 covers the CMOS chip 120. The lens group 130 includes a lens mount 132, a plurality of lenses 134, an infrared filter 136 and a lens barrel 138. The lens mount 132 is fixed on the base 110 and the lenses 134 are disposed inside the lens barrel 138. The lens barrel 138 is fixed on the base 110 and the infrared filter 136 is disposed between the lenses 134 and the bottom of the base 110.
The lens barrel 138 has a pinhole 139 so that light rays from the exterior can pass through the pinhole 139 to reach the lens group 130. The lenses 134 focus the light rays onto a sensing area 122 of the CMOS chip 120 and the CMOS chip 120 detects the light falling on it. The infrared filter 136 filters the infrared portion of the incoming light rays to prevent the CMOS chip 120 from overheating. Hence, the life of the CMOS chip 120 is increased.
In the conventional technique, the lens group 130 includes a large number of components so that the material cost is high and the assembling time is long. As a result, the conventional CMOS image-sensing module 100 not only has a high production cost but is also too bulky to use in small electronic products such as a cell phone or a pinhole camera.